Concentrator.



F. 0. STERRETT.

Patented Apr. 23,1918.

3 SHEETS-SHEET l.

F, 0. STERRETT.

CONCENRATOR.

APPLICATION man ocT.2.1914.

15963995@ Patented Am. 23,1918.

3 SHEETS-SHEET 2.

WMM/neo @@Myw@ 52M wwf/74% www,

' E. o. sIEIIIIET.

CONCENTRATOR. APPLICATION EIIED ocT. 2. 19m.

mme@ Apr. 23, 1918.

3 SHEETS-SHEET 3.

hmmm A FRANK 0. STERRETT, OF COLORADO SPRINGS, COLGRADO.

CONCENTRATOR.

neonato.

Specification of Letters Patent.

Patented Apr. 23, 1915.

Application filed October 2, 1914. Serial No. 864,642.

To all whom it may concern Be it known that I, FRANK 0. STERRETT, acitizen of the United States, residinof at Colorado Springs, in thecounty of lill aso and State of Colorado, have invented certain new anduseful Improvements in Concentrators, of which the following is aspecification.

My invention relates to apparatus for treating placer sands, tailings,or any material containing values, which may be separated therefrommechanically because of the difference in their specific gravities, andhas for its object to provide certain improvements in the constructionand operation of the apparatus, as will be hereinafter more definitelypointed out and claimed, reference being had to the accompanyingdrawings, in which t Figure 1 is a vertical longitudinal sectional viewof my improved concentrator, taken on line l--l of Fig. 2.

Fig. 2 is atop plan view of the same.

`Fig. 3 is a vertical transverse sectional view, taken on the lineIll-lll of Fig. 2.

Fig. t is a detail sectional view of one of the belt rollers.

l? 5 is an enlarged detail View partly in section of the vibratingmechanism for the concentrating belt and its carrier.

Fig. 6 is a diagrammatic view illustrating my improved apparatus inassembled connection with a wet screen for the material, the twoproducing a unit or body.

Similar numerals of reference denote corresponding parts in the severalviews.

ln the said drawings, the reference numeral 1 denotes a tank or chamber,which may be of wood, metal or other suitable material and braced in anydesired manner. Said tank preferably is mounted on wheels 2, whereby itmay be run on a track 3 for convenience in transportation and operation.At one end at its bottom, the tank 1 is provided with a transversepartition 4, between which and the adjacent end of the tank is disposeda screw conveyer 5 .adapted to convey material dropped thereon out atone side of the tank, where it will be taken up by a bucket conveyor 6,disposed at an angle 'on one side of the tank 1 in a casing 7 The bottomof the tank 1 is also provided with a vertical transverse partition 8,supporting one end of-an inclined false bottom 9, eX- tending to theother end of the tank, said tank having disposed therein at said endanother transversely disposed screw conveyer 10 adapted to feed thematerial through the side of said tank to a bucket conveyor 11 disposedin a casing 12. `With in thetank 1 are located two angle brackets orsupports 13, one of the same being bolted to one side of the tank, andthe other being bolted to and carried by a support h within the tank,and located some distance from its opposite side. Said brackets 13 carryat their upper bent ends the bearings 15 for the central shaft 16 of abelt concentrator. This belt concentrator embodies side frames 17suitably braced and carrying at its ends the shafts 18 of drums 19,around which the concentrating belt 20, hereinafter described, isdisposed, and by which the same is run. The drums 19 may be of anysuitable construction, and in Fig. 4;, l have shown them as formed ofend pieces 21 and an intermediate bracing member 22, the space betweenthe end pieces 2l being covered by a spool of sheet metal wrappedtherearound, and around which the belt 20 is disposed. While saidconcentrating belt is supported centrally upon the shaft 16, it is alsosupported adjustably at its ends, the lower end being supported bychains 2-1 attached to each of the side frames 17 by links 25, saidchains at their upper ends being supported by screw threaded hooks 26passing through a transverse cleat 27 on the top of the tank 1, andbeing capable of minor adjustment by means cf a nut 28. Links 29,similar to the links 25, and bolts 30 passing through a transverse cleat31, support the upper ends of the side frames, the bolts 30 passingfreely-through the cleats 31 and being retained in place by nuts 32,springs 33 being interposed between said nuts and the top of the cleat,whereby a yielding action is imparted to said bolts 30 and the upper endof the belt conveyer, as readily will be understood.

Power is applied to the device from a main shaft 341 driven from a powerpulley 35 and disposed longitudinally of and outside of the machine atone side thereof at the top, and supported in suitable bearings 36,mounted on the cleats 27 and 31, and also on additional transversecleats 87. At its end opposite the power pulley 35, the shaft 34 hasmounted thereon a pulley 3S from which a belt 38 runs transversely ofthe machine to a similar pulley 39, mounted upon a shaft 40 carried inbearings 41 upon the cieats 81 and 37 upon the opposite side of llG 'the machine from, but parallel to, theV main shaft 34. At its inner'endthis shaft 40 is provided with a wheel 42 to which is eccentricallyconnected a rod 47, by means of a pin 48, said rod extending downwardlyand being connected at its lower end with a bell crank 49, mounted upona bracket 50 attached to the side of the tank `1. rlhe opposite arm ofsaid bell crank 49 is pivotally connected with the outer end of abifurcated arm 51, the ends of the latter passing freely through plat-Qs52, which in turn are movably disposed upon the Vreduced end 53 of theshaft 16 of lthe belt co'nveyer,'said reduced end 53 carrying a nut 53fixed thereon. Disposed between the plates 52 and surrounding thebifurcated ends `of the arm 51 are coiled springs 54, while upon theouter ends of sai arms are lnuts 55, similar nuts 56 being fixed uponsaid arms outside of the outer plates 52. The'drive for the belt 2O isprovided from the drive shaft 34 through a pulley 57 on said shaft l34intermediate its length, a belt 58 running from said pulley to asimilar' pulley 59, carried by a shaft 60, -that in turn is providedwith a worm 61 meshing with lworm gear 62, fixed to a transverse shaft63, said pulley 59, shaft 60 and worm 61 being Vcarried by a suitablebracket 64 mounted upon the outside of the tank 1. The 'transverse shaft63 vextends within the tank and part way `across "the same, terminatingat a Vbracket 65 bolted tothe underside of a transverse bolsterv66 thatin turn is vfixed vto the underside ofthe cleats 37. This bracket 65carries'a sprocket wheel 67 around which a sprocket chain 68 is carriedand which in turn :passes around a larger sprocket wheel 69 `-freelymounted on the shaft 16 of the concentrator table. Also mounted uponsaid shaft 16 but `keyed to the sprocket wheel 69 is a "smaller sprocketwheel 70 from which a sprocket chain 71 passes to a similar sprocketwheel 72 at the upper end of the belt conveyer, said sprocket wheel 72being fixed tothe 'shaft 18 of the Lipper drum around which the beltpasses so that said druml willfbe driven thereby, and the moytio-nefsaid'drum imparted to the kbelt 20.

A suitableffeed chute 7 3 is provided for the machine, the materialbeing dumped upon the table '74 at vthe upper end thereof and fed intosaid chute, the lower end of said chute preferably terminating justabove the surface of the belt 20 at substantially itslongitudinal-center. v

In'operation the tank 1 is filled with water lto the level of the dottedline in Fig. 1, which will just submerge the belt conveyer. Motion isimparted to the drive shaft 34 lfrom pulley 35 by any suitablesource ofpower, which in turn, through the sprocket `chain 68 and the connectionshereinbefore f Y described, will impart motion to the belt v20,

the relative 'adjustment of the parts of the machine being such that themovement imparted to said belt will be comparatively slow, say threefeet per minute, the upper surface of said belt traveling upwardly, inthe direction of the arrow in Fig. 1. The material to be treated beingfed through the chute 73, preferably in a wet state, will be depositedupon the belt 2O at substantialhv its center, and beneath the waterlevel, where the action of the water will be to permit the gold or othervalues, on account of their greater specific gravity, to be depositedimmediately upon the belt, and will cause the o gangue to overlie saidvalues and be carried gradually down the belt. As shown in Fig. 2, Ihave provided the outer surface of my belt 20 with a series of curvedpockets or `riflles 78, said pockets or riffies being disposedtransversely of the belt and being deeper at their centers than at theiredfves,

'gangud the co-nveyer is given a bodily oscillatory movement by means ofthe rod 47 driven as hereinbefore described, said rod through the bellcrank 49 and the bifurcatod arm 51 imparting tothe shaft 16, on whichthe side frames 17 of the belt conveyer are fixed, a gentle but rapidoscillatory movement. It will be understood that the eccentric movementof the rod 47 will impart a reciprocating movement to the bell crank 49,which 'in turn will lbe imparted to the bifurcated arm 51, and becauseof the spring connection between said arm and the shaft 16, said motionwill be imparted to said. shaft but will be cushioned most efficiently.Thus upon a movement of the arm 51 inwardly, the outer plate 52 will beforced away from the nut 53 on the reduced portion 53 of the shaft 16and 'will tend to compress the springs 54 against the inner plate 52,thereby imparting a transverse bodily movement to the shaft 16 but witha cushioned effect. Similarly upon a movement Vofthe bell crank 49 inthe opposite direction,

the inner plate 52 ywill tend to be carried away from the shaft 16, thusagain comcushioning effect. The result of this meclr anism is that theconveyer belt and its supporting frame are given a rapid but cush- CFIioned bodilv reciprocating movement while said belt is traveling on itspulleys, the result being that the separation of the values from thegangue is more readily eliected, as will be well understood by thoseskilled in the art.

By mounting the belt conveyer upon the shaft 16 and supporting its endsas described, I provide for a better disposition of the weight of saidcarrier. Its immersion in the tank will naturally decrease its speciiicgravity, and by suspending its Ytour corners in the manner shown, theweight of the same is lifted from the central shaft 16 and the beltmaybe run with very much less power than would be required with the samesupported from beneath. Furthermore, by cushioning the support of theupper ends of .the belt conveyer through the springs 33, it will beevident that I further minimize the jar upon the belt 20, due to itsrotation and to its bodily reciprocating movement hereinbeforedescribed. In fact by cushioning the blow of the reciprocation impartedto the conveyer and by supporting it resiliently at its upper end, so asto take off the weight of the same from the central shaft 16, I haveprovided a construction which in practice has obtained a maXimum effectin the separation of the values. rI`hus, while I obtain the movementsheretofore deemed necessary in concentrating` tables, at the same time Iproduce them in a manner to minimize the shock, whereby values are notthrown from the side o1 the table, and at the same time producesuiiicient jar to deposit the values at the lowermost points in thecurved riiiles 78 described. It will be understood that in theconcentration of values under water the lighter material will leave thetable immediately upon being deposited upon the same from the chute 73,and will be held in suspension or in a state approximating the same,this efrect beine' carried out with the lighter material down to theheavier, which, of course, are the values. For this reason with a stillbody of water and a belt moving at a comparatively slow speed, and atthe same time being subjected to a gentle but rapid vibration, and beingcushioned against eXcessive jars in any direction, I effect a. mostcomplete separation of the values from the ore, and deposit the same asa concentrate over the upper drum 19 and at the lower end of the falstbottom 9, where the same may be removed by the screw conveyer 10. Intact I have found that the cushioning of the concentrator belt is of theutmost importance in the practical operation ofthe device, in that by socushioning the same I provide for a thorough separation of the ganguefrom the values, and the deposit of the latterin the riiiles 7 5 wherethey will remain without danger of being j arred out because ot' undueshocks which result necessarily with an uncushioned separator. Thegangue passing down the belt 20 is discharged upon the screw conveyer 5and upon that side of the partition a and is conveyed through a suitableapertureA in the side of the tank to the bucket conveyer 6 in thecasing, 7, whereby it is elevated and discharged in any suitable manner.This elevation and discharge of concentrates in a similar manner isaccomplished by the buckets 11 in casing 12, which receive and removethe values fed through one side ot' the machine by the screw conveyer10.

In employing a concentrating belt or table submerged in liquid, it ishighly important, first, that the operative parts be so disposed withrespect to the belt or table that no grease from the same will drop uponthe belt or table, and further that the operative parts immersed in theliquid be reduced to a minimum. It will be observed that in my presentconstruction, the main shaft 34- and its allied parts are disposedoutside of the tank, while the operating vibrating mechanism, whiledisposed inside of the tank 1, is located to one side of the beltproper, thereby reducing the danger of grease and oils to a minimum.Furthermore, by employing the bell crank 49, I have reduced the rotatingparts immersed in the liquid to a minimum, as the employment of aneccentric at this point would increase materially the undue wear andfriction due to its immersion in gritty liquid, such as is found inthese devices. Again by disposing the operative mechanism in the mannershown, I have provided for driving all of the parts without thenecessity of a side penetration lof the tank 1, thereby eliminating allstuiifing boXes and devices of that character, necessarily producingundue friction and wear.

In Fig. 6, I have shown a diagrammatic view oit my improved concentratorin connection with a wet screen. It will be understood that the materialto be treated will respond more readily to the separating action itsubmitted to the concentrator in a wet state, and when placer materialis being treated taken from a bank or bed of a stream, it is necessarythat it be screened before it is introduced into the concentrator toremove the larger materials. In order to present the material in a wetstate to the concentrator, and at the same time to obviate the waste ofwater, which in certain localities is a desideratum. I provide forscreening the material with water taken from the tank l, the said waterbeing discharged, together with the screened material, back into theconcentrator tank. Thus, I mount the screen 75, which may be of anysuitable construction, and driven in any suitable manner, so as todischarge upon the loo table 74 of the chute 73 and connect said vscreenby means of a pipe 7 6 and an interltank 1 through the chute 73. I havefound in practice that VWhile it is highly essential lthat the Water Vinthe tank 1 should be in a quiescent state during the operation of the'concentrating belt, that the Withdrawal of the water through the pipe 76 necessary for the screening operation 'will vin no Wise disturb thevolume of Water in the tank, at least to an extent to interfere With theeffective operation of the concentrating device.

y I also'eontemplate the-employment of my improved concentrating tank aswell as the screening device 75 in 'connection with a suitable dredge orshovel (not shown), said dredge or shovel being mounted upon Wheels torun on the track 3 with the tank 1, but being disposed in front of saidtank and its screen 75 in such position that it may discharge directlyinto said screen 75. By this assemblage of units, I provide for anuninterrupted operation of the device from the picking up of thematerial to be treated to its discharge separated as concentrates andgangue from the tank 1.

.I have shown kand described my improvements as particularly adapted foruse 11i connection with an endless belt concentrator submerged in a bodyof still Water or other liquid, but I Wish it to be understood that I donot limit myself to this application of the various novel features ofthe invention, as the saine may be applied with equally advantageousresults to a concentrating belt not immersed in liquid, or even to acoiicentrating table.

Having thus described my invention, What I claim as new and desire tosecure by Letters Patent, is:-

1. In a concentrator, an endless concentrating belt, a supporting framefor the same, a fixed retainer in which said supporting frame is pivotedintermediate its length, means for suspending said supporting frame fromits four corners and for cushioning said suspending means and adapted totake the Weight of said belt and frame off of said fixed retainer, andmeans for driving said belt.

2. In a concentrator, an endless concentrating belt, a supporting framefor the same, a fixed retainer in Which said supporting frame is pivotedintermediate its length, means for suspending said supporting frame fromits four corners and for cushioning said suspending means and adapted totake the Weight of said belt and frame "off of said fixed retainer,means for drivino` said belt, and means for imparting a `vibiatorymovement to said belt.

3. In a concentiator, an endless concentrating belt, a supporting famefor the same, -means for pivoting said supporting frame intermediate itslength, means for suspending said supporting frame from its four cornersand for cushioning said suspending means for resilient verticalmovement, and means for driving said belt by poiver applied initially totheI axis of said intermediate pivot, thereby permitting a rockingmotion to said supporting frame and belt.

et. In a concentrator, an endless concentrating belt, a supporting framefor the same, means for pivoting said supporting frame intermediate itslength, means for suspending said supporting frame from its four cornersin a position inclined to the horizontal, means for cushioning the sns-`pension 'means supporting the upper ends of the frame, said suspendingand cushioning means being adapted to take the Weight of the frame offthe pivoting means, and

means for driving said belt by power applied initially at the axis ofthe said intermediate pivot, thereby permitting a rocking motion of saidsupporting frame and belt.

5. In a coneentrator, a concentrating belt, a supporting frame for thesame, a transverse shaft upon 1vhich said supporting frame is fixedintermediate its length and with which it may be rocked, means foriinparting a longitudinal vibratory movement to said shaft, andmechanism mounted in part upon said shaft for driving said belt.

6. In a concentrator, a concentrating belt, a supporting frame for thesame, a transverse shaft upon which said supporting frame is iixedintermediate its length and with which it may be rocked, means foriniparting a longitudinal vibi'atory movement to said shaft, means forcushioning the shocks vin each direction of vibration, and mechanismmounted in part upon said shaft for driving said belt.

Y 7. In a concentrator, a concentrating belt, a supporting frame for thesame, a transverse shaft upon which said supporting frame is fixedintermediate its length and With whichv it may be rocked, means forimparting a longitudinal vibratory movement to said shaft, means forcushioning the shocks in each direction of vibration, and a sprocketchain drive for said belt having certain of its sprocket Wheels mountedfreely on said shaft.

8. In a concentrator, a concentrating belt, a supporting frame for thesame, a transverse .shaft upon which said supporting frame is pivotedintermediate its length, means for suspending said supporting frame fromits four corners and for cushioning Lacasse said suspending means andadapted to take the weight of said belt and frame 0d' of said transverseshaft, and means for imparting a longitudinal vibratory movement to saidshaft.

9. ln a concentrator, a concentrating belt, a supporting frame for thesame, a transverse shaft upon which said supporting frame is pivotedintermediate its length,

means for suspending said supporting frame from its four corners and forcushioning said suspending means and adapted to take the weight of saidbelt and frame off of said transverse shaft, means for imparting alongitudinal vibratory movement to said shaft, and means for cushioningthe shocks in each direction of vibration.

l0. In a concentrator, an endless concentrating belt, means for drivingthe same, a supporting frame for said belt, a transverse shaft uponwhich said frame is pivoted intermediate its length, a power shaft, arod reciprocated from said power shaft, a bell crank reciprocated bysaid rod, connections 1 between said bell crank and the pivotal shaft ofsaid frame, and springs interposed between said bell crank and saidpivot shaft for cushioning the vibratory movement imparted to said shaftin each direction.

1l. In a concentrator, a fluid containing tank, an endless concentratingbelt therein, means for driving said belt, a supporting frame for saidbelt, a transverse shaft upon which said frame is pivoted intermediateits length, a power shaft disposed at the top of said tank, a rodreciprocated from said power shaft and extended into the tank, a bellcrank reciprocated by said rod, connections between said bell crank andthe pivot shaft of said frame, and springs interposed between said bellcrank and said pivot shaft for cushioning the vibratory movementimparted to said shaft in each direction.

ln testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses. l

FRANK O. STERRETT. Witnesses:

PERCY B. HILLS, SALLIE BOLAND,

Genies o1? this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents.

Washington, D, C.

